Railway braking apparatus



Oct. 7, H. BONE I RAILWAY BRAKING APPARATUS Filed Dec. 8, 1927 wwa NNSNN lllll II INVVENTOR." /4'A,. one,-

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Patented Oct. 7, 1930 UNITED STATES PATENT oFF cE SWITCH & SIGNAL COMPANY, 01E SWISSVALE, PENNSYLVANIA, A CORPORATION OF RAILWAY BRAKING-APPARATUS Application filed December s, 192?. Serial no/238,551.

My invention relates to railway braking apparatus, and particularly to apparatus of the type comprising a braking bar located in the trackway-v and means for at times urging the braking bar into engagement with a part of a railway vehicle. a

I will describe one form ofrailway braking apparatus embodying my invention, and will i thenpoint out the novel features thereof in claims.

The accompanying drawing is a view,

partly diagrammatic, illustrating one form of railway braking apparatus embodyin my b When winding 9 is energized, the left-l1and invention.

Referring to' the drawing, the reference characters t andt designate the two track rails of a stretch of railway track provided with railway brakingv apparatus. In the form here shown, this apparatus comprises two braking bars 5 and 6 located on opposite sides of the rail 4 and arranged to engage the opposite sides of a wheel of a railway Vehicle passing along the track. Two similar bars 5 and6? are located on opposite sides of the track rail 4. The braking bars 5, 6, 5 and 6 are controlled by a fluid pressure motor device designated by the reference character A. As here shown this motor,

the braking bars are in their non-braking p0- sitions. When the piston is driven. to its right-hand position in cylinder 1, the braking bars associated with each of the track rails are urged toward the corresponding rail, so as to engage the sides of a wheel of a railway vehicle, .bars 5 and 5 'moving to-- ward the right and bars 6 and 6 moving toward the left. It should be pointed out that since the braking bars arenrged into engage ment with the car wheels by pressure tending to movethe; piston 2 toward the right, the total braking force exerted upon the car, depends upon the pressure which is effective to move the piston 2. It will be observed from the drawing that the plunger 3 hasa com paratively large diameter, so that the piston 2 is in effect a differential piston, that is to say, the areas upon whichipressures in the two ends of the cylinder 1 are effectiveupon the piston 2 are unequal. V I propose to control the admission of fluid pressure in'both ends of the cylinder 1 to provide a plurality of different total eifective pressures available for urging the braking bars toward their braking positions. 3 i V v l v The reference character B designates a magnet valve comprising a valve stem 8 pro vided with an armature 8 and a winding 9.

end of cylinder 1 is connected with a suitable sourceof fluid pressure, not shown in the drawing, throughpipe 10, valve B, and pipe 13. When winding 9 is de-energized,-however, the valveB is closed, so that the supply offiuid pressure from pipe 10 to cylinder 1 is discontinued. A second valve'G comprises a valve stem 8 which is also, provided with a winding I9 and an armature 8, and is so arranged thatwhen winding 9 is deeenergized cylinder 1 on the left-hand side of piston 2 is HERBERT 'L. BONE, or PifIJTSBURGH, PENNSYLVANIA, 'Assreivon rro TI-IE union connected'with atmosphere through pipe 14:,

valve C and port 11. If, however, winding 9 of valve Cis energized, valve stem 8, is

drawn downwardly to blank pipe 14 and prevent the escape of fluid pressure from cylinder 1. third valve, designated by the reference character D, controls the supply of fluidpressure to the right-hand end of cylinder 1g Vhenwinding-Q of this valve isdeenergized, pipe 12 communicating with the right-hand end ofcylinder 1 is connected with atmosphere through port 11. Vhen winding 9 of valve D is energized, however,

valve stem Sis moveddownwardlyand pipe 12 is'dis'connected from port 11 and is connected with a source of fluid pressure through pipelO.

The three valves B, C and D are controlled in part by a manually operable circuit con troller designated in general by the reference character K and comprises a pivoted lever 18 which may be moved into a plurality of positions indicated in the drawing by dotted lines designated serially from I to VI. When the lever 18 occupies position I, the lever engages a fixed contact 25, when the lever occupies position II, all of the contacts of circuit controller K are open, the lever being illustrated in this position in the drawing. The lever 18 also co-operates with certain other fixed contacts so that contact 1821 is closed when the lever occupiespositions III or IV, contact 1822 is closed when the lever occupies positions III, IV, V, or VI, contact 18 -23 is closed when the lever occupies position IV, and contactlS-2/1 is closed when the lever occupies position VI. Associated with the circuit controller K is a push button designated, by the reference character 19. This push button is normally closed but is arranged to be'opened manually.

The reference character Gr designates an automatic circuit controller comprising a pressure responsive unit 16, such for example,

as a Bourdon tube, which is connected with the left-hand end of cylinder 1 through a pipe 15, and which controls a-contact, 17 so thatwhen the pressurein the Bourdon tube 16 exceeds a predetermined value,the contact 17 willbe opened. 7

For purposes of explanation, I will assume that pipes '10 are supplied with fluid at a pressure of 100 pounds per square inch, and that the contact 17 of circuit controller G is opened when the pressure in the left-hand end of cylinder 1 exceeds 75 pounds per square inch,-and I will alsoassume that the diameters or" piston 2 and plunger 8 are 12 inches and 8 inches, respectively. p

As shown in thedrawing, with lever '18 of circuit controller K in position II, all of the valves B, G and D are de-energized and the piston 2 is in its left-hand position, so

that-the braking bars located in the trackway are in their non-braking or ineffective posltion. I Wlll first assume that the operator wishes to make a light brake application.

To accomplish this result, he moves lever 18 to position III. Current then flows from a suitablesource of energy such as a battery J throughwire 26, push button 19, wire 20, contact 18 22, wires 33-and 27, winding 9 of valve C, and wires 28 and 29 back to battery J. Valve C is therefore closed to blank pipe 14 and thereby prevent escape of fluid pressure from the left-hand end of cylinder 1. At the same time, current flows over the circuit just traced as faras wire 33, and thence through wire 87, contact 17 of circuit controller G, wires 34 and 85, winding 9 of valve B, and wires 36 and 29, back to battery J. When this circuit is closed, valve B opens, and fluid. pressure is supplied to the left-hand end of cylinder 1. But as soon as the pressure in the left-hand end of the cylinder exceeds 75 pounds per square inch, contact 17 opens, and the pressure is thereafter maintained at 75 pounds per square inch. WVith lever 18 1n position III, current also flows from battery 7 inch is sup lied to the right-hand end of the cylinder. n the assumption that piston 2 is 12 inches in diameter and the plunger 3 is 8 inches in diameter the total force effective to move the piston toward the right isitherefore approximately 3500 pounds.

Should the operator wish to increase the braking force supplied to the braking bars, he moves lever 18 to position IV- The-circuits already traced for valves C. and D are still closed with the lever inthis position, and the circuit'for valve B through contact 17 ofcircuit controller G is also closed. In addition to this latter circuit, however, still another circuitis closed for valve B from battery J, over wire 26,push button 19, wire 20, contact18-23 of circuit controller K, wires 32 and 35, winding 9 of valve B, and wires 36 and 29 back to battery J. When this circuit is closed, a branch is completed around contact 17-01 circuit controller Gr so that valve'B is held open to supply the full pressure of 100 pounds per square inch to the left-hand end of cylinder 1. Under these conditions, then, both ends of cylinder 1 are supplied with fluid pressure at 100 pounds per square inch, but due to the unequal areas of the opposite sides of piston 2, the total force now effective to move piston 2 to the right is approximately 6300 pounds.

Furthermore, if the lever 18 is moved to position V, contact 18 21 of circuit controller K is openedand valve D closes to connect the right-hand end of cylinder 1 with atmosphere. lVith the lever in position V, valve B. I is supplied with current over contact 17 of. circuit controller G and valve C is closed. Under these conditions, vno pressure is supplied to the right-hand end of cylinder land the left-hand end of the cylinder is supplied with fluid pressure at 75 pounds per square inch. vThe force eflective to move the piston to the right is therefore approximately 8500 pounds. Finally, when lever 18 occupies position VI, the closing of contact 1824: suppliescurrent to winding 9 from battery J independently of contact 17 of circuit controller G over a. circuit similarv to the circuit traced for this winding through contact 18-,-23. The valve D is still de-energized so that the right-hand end of cylinder 1 is connected with atmosphere and pressure of 100 pounds per square inch is supplied to the f .D are open. As an alternative, he may de-energize all of the valves by opening push button 19. In either event, the two ends of cylinder 1 are connected with atmosphere so that no pressure is exerted on the braking bars. The operator next moves lever 18 to position I, thereby closing contact 1825, whereupon current flows from battery J, through wire 26, push button 19, wire 20, contact 1825, wires 39 and 30, winding 9 of valve D and wires 89 and 29 back to battery J. The valve stem 8 of valve D therefore moves clownwardly and fluid pressure is supplied to the right-hand end of cylinder 1. As a result, piston 2 is driven to the left, and the braking bars are moved to their non-braking positions. With the braking apparatus thus released, the operator returns lever 18 to the position shown in the drawing, thereby deenergizing valve D and restoring the apparatus to its normal condition. It will be plain from the foregoing explanation that by regulating the fluid pressure supplied to the opposite sides of a difierential piston, I can control a fluid pressure motor for operating.

railway braking apparatus with a minimum number of line wires between the motor and the circuit controller K. It should be pointed out that although I have mentioned certain values of fluid pressure and certain diameters for the difl'erential piston 2, these particular proportions are not essential but are only given by way ofillustration. It should also be understood that although I have herein disclosed apparatus for providing only four dilierent operating pressures, the control circuits could be modified to increase to any reasonable limit the number of steps by which the efiective braking pressures are varied. 1

Although I have herein shown and described only one form of railway braking apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from i the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway braking apparatus comprising a braking bar located in the trackway, a fluid pressure motor for actuating said bar and comprising a cylinder and a piston reciprocable in such cylinder, a manually operable circuit controller, means controlled by said circuit controller for at times supplying different pressures to the two ends of said cylinder, and means also controlled by said circuit controller :forat otherwtim'es supplying differentapressures to; one rend only of said:

Railway 5 braking apparatuscomprisinga braking barlo'cated: inath'e.trackway, a fluid pressure*motor 'for actuating said barand comprising a cylinder and a pistonreciprof-a cable in :such 1 cylinder, a contact responsive to the "pressurein one end? ofthe cylinder, a manually operable circuit controller, and means controlled by. said circuitcontroller and by said contact for. at times supplying the two ends of the cylinder with fluid at different pressures.

3. Railway braking apparatus comprising a braking bar located in the trackway, a fluid pressure motor for actuating said bar and comprising a cylinder and a piston reciprocable in such cylinder, means for at times supplying fluid pressure selectively to the two ends of said cylinder, and means for at other times supplying fluidpressure simultaneously to both ends of the cylinder.

4. Railway braking apparatus comprising a braking bar located in the trackway, a cylinder, a piston reciprocable in the cylinder and carrying a plunger connected with the braking bar so that the effective areas of the two sides of the piston are unequal, means for at times supplying fluid pressure to one end only of said cylinder, and means for at other times supplying fluid pressure to both ends of the cylinder simultaneously. 7

5. Railway braking apparatus comprising a braking bar located-in the trackway, a fluid cylinder, a piston reciprocable in the cylinder and carrying a plunger connected with the braking bar so thatthe effective areas of the i two sides of the piston are unequal, a manual-- 1y operable circuit controller, and means for supplying the two ends of said cylinder with equal pressures or with unequal pressures depending upon the position of said circuit controller.

7. Railway braking apparatus comprising a braking bar located in the trackway, a fluid pressure motor for actuating said bar and comprising a cylinder and a piston reciprocable in such cylinder, a first winding controlling the admission of fluid pressure to one end ofthe cylinder, a second winding for controlling the. admission of fluid pressure to the other end of the cylinder, a contact responsive to the pressure in said one end of the cylinder, a source of energy, and manuaL 1y controlled means for' connecting saidsourcewith said one winding in series with said contact and for simultaneously connecting, said source directly with said second winding. I

vIn testimony whereof I aflix my signature. I

-HERBERT L. BONE. 

